Yarn twisting apparatus



J. RASCHLE March 19, 1968 YARN TWISTING APPARATUS 2 Sheets-Sheet 1 Filed May 2, 1966 INVENTOR. dasfiF PAscmc- March 19, 1968 3 RASCHLE YARN TWISTING APPARATUS 2 Sheets-Sheet 2 Filed May 2, 1966 R r mm w F United States atent 3,373,554 Patented Mar. 19, 1968 Claims This invention relates to apparatus for twisting yarn to texture same, and more particularly, to apparatus useful in false twisting of yarns.

Methods and apparatus for texturing textile yarns are already known according to which a high false twist is imparted to the yarn by means of a twist tube, the yarn being set while in the twisted condition. The twist tube, which is rotated about its longitudinal axis by suitable means such as a belt drive, motor or the like, is equipped with means such as a pin or projection arranged to engage the yarn and twist same as it moves through the tube. While such apparatus have achieved a high degree of efliciency and commercial acceptance, the speed of rotation of the tube is nevertheless limited by the neces sary bearings.

Thus, methods and apparatus have been developed whereby the twist is imparted to the yarn by direct frictional contact with a rotating surface. For example, it is known to provide two belts running in opposite directions with the yarn passing between and in contact with them and in a direction transverse to the axis of movement of the belts. The belts impart a twist to the moving yarn by reason of the frictional contact of same. By these means, a greater number 'of turns per meter is imparted to the yarn than is achieved by the twist tubes already alluded to. Nevertheless, it is true that under certain conditions, some slippage may occur between the yarn and the belts in which case intolerable variations will occur in the number of twists per meter of yarn.

-Accordingly, I have conceived a novel apparatus for false twisting yarn that eliminates the foregoing difiiculties and disadvantages. Essentially, I contribute means whereby on the one hand the friction contact between the yarn and the twist imparter is sutficient to assure practically no slippage of the yarn and, on the other hand, the friction losses in the advancing yarn are very low so as to obviate breakage.

'An important feature of my invention concerns the provision of a friction twist imparter for texturing textile yarns, according to which discs or belts drivable in opposite directions are pressed together at the zone through which the yarn passes between them. Actually, any convenient pressure means may be employed, but I prefer to utilize magnetic force for this purpose.

As another feature of my invention, part of the discs or belt drive mechanisms may be formed of flexible, nonmagnetic elastomeric material such as rubber or rubberlike material with a high coefiicient of friction relative to textile yarns. Additionally, I prefer that at least part of the drive belts or discs consist of permanently magnetic material, or contain a coating or layer of magnetic material such as sheet iron, iron wire, powder or the like whereby-they may be urged together at the twist zone by magnet positioned for that purpose.

The friction twist imparter according to the invention is suitable for false twisting of endless threads or filament bundles respectively as well as of staple fiber yarns ofpolyamides (polyhexamethylene adiparnide, condensates of epsilon amino-caproic acid or ll-amino-undecanoic acid), polyester (polyethylene glycol terephthalate), material on vinyl basis (polyacrylonitrile) or polyolefines (polypropylene), furthermore, cellulose acetate as well as mixed yarns of thermoplastic fibers and non-thermoplastic natural fibers.

There has thus been outlined rather broadly the more important feature of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will form the subject of the claims appended hereto. Those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures for carrying out the several purposes of the invention. It is important, therefore, that the claims be regarded as including such equivalent construction as do not depart from the spirit and scope of the invention.

A specific embodiment of the invention has been chosen for purposes of illustration and description, and is shown in the accompanying drawings, forming a part of the specification, wherein:

FIG. 1 is an elevational view of one example of my invention;

FIGS. 2 to 4 illustrate constructions alternative to that of FIG. 1;

FIG. 5 is an elevational view illustrating a further example of my invention;

FIG. 6 is a plan view of yet another example; and

FIG. 7 is a sectional view taken along the lines 7-7 of FIG. 6.

Referring now to the drawings, and to FIG. 1 in particular, I have shown a yarn twisting device comprising two circular discs 1 and 2, the axes of which are parallel and positioned so that portions of opposite surfaces overlap and contact one another, i.e., a portion of the upper surface of discs 1 is positioned directly under and in contact with a portion of the lower surface of disc 2 to form a yarn twisting zone therebetween. Disc 1 is mounted on a circular support 3 of non-magnetic material and which is itself centrally mounted on the end of a rotatable shaft 4. The other disc 2- is centrally mounted on the end of shaft 5.

The shafts 4 and 5 are driven in the directions indicated by the arrows A and B, respectively, by suitable means, which will be well known to those skilled in the art and therefore notshown. Thus, it will be seen that the overlapping portions of the discs 1 and 2 move in opposite directions and impart a false twist to a textile yarn 6 passing between the discs. Conventional means (not shown) may be used to feed and take up the yarn 6.

By way of example, the discs 1 and 2 may consist of a non-metallic, flexible material such as rubber into which Koerox powder (BaO.6Fe U has been worked.

- The overlapping edges of the discs 1 and 2 are of opposite magnetic polarity, as indicated, and attract one another; and, because of the flexibility of the discs, the

I edges.v of the discs mayobend on either side-of the yarn 6 atfordin close pressure each against the other to substan= tially eliminate any tendency of the yarn to slip.

Turning now to FIG. 2, I have shown a construction similar to that of FIG. 1, but in which an ordinary rubber disc 7 replaces disc 1, and a flexible disc 8 containing a filling of permanently magnetic material is mounted on the shaft above the disc 2 and spaced therefrom about 1 mm. An upper supporting plate 9 is secured to the upper surface of the disc 8. The facing edges of discs 2 and 8 are similarly polarized and repel each other whereby the lower marginal surface of disc 2, due to its ability to flex, is pressed against the upper marginal surface of disc '7 to impart a false twist to the yarn 6 passing there'between substantially without slippage.

In FIG. 3, the support 3 has an ordinary rubber disc 7a mounted thereon, but of lesser depth than the disc 7 of FIG. 2; and an annular permanent magnet 10 is inserted into a suitable recess in the edge of support 3 by which the marginal edge of disc 2, comprising flexible, permanently magnetic material, is attracted.

As shown in FIG. 4, a non-flexible disc of hard rubber or the like is mounted on support 3 and partially overlaps the disc 2 which includes permanently magnetic material. Beneath the disc 20, in the area of overlap between discs 2 and 20, I position a permanent horseshoe magnet 11 with its poles arranged to attract the disc 2 and thus press its marginal edge against the marginal edge of disc 20. Disc 2 may consist of magnetic material, or may contain iron powder or may have an intermediate layer of thin sheet iron, for example; and of course, an electromagnet may be used in lieu of the permanent magnet 11.

In FIG. 5 I have illustrated a twisting device having two circular discs 12 and 13 each mounted on the end of shafts 14 and 15, respectively, adapted to be rotated in the directions shown by the arrows C and D, respectively. The discs 12 and 13 are symmetrically arranged to form an angle of between 10 and 45 and preferably approximately 30 between the axis of the moving yarn 6 and the plane of the surfaces of the discs. The discs contact each other at the zone T where twisting takes place and through which the yarn passes. These discs may be formed of material as described in connection with the discs of FIG. 1, and are polarized to press against one another closely and firmly to engage the yarn 6.

Referring now to FIGS. 6 and 7, there are shown two belts l6 and 17 overlapping one another at right angles and moving in the directions indicated respectively by the arrows E and F. The belts may consist of rubber and one of the belts, say 17, may contain an intermediate layer of iron powder, sheet iron or iron wire or the like. Beneath the overlapping area of the belts a magnet 18 is positioned to attract belt 17 towards belt 16 andthus impart a false twist to the yarn 6 passing therebetween at an angle of 45 to the lines of travel of the belts without substantial slippage.

EXAMPLE A multifilament yarn consisting of p-olyhexamethylene adipamide and having a titer of 70/23 denier coming from a delivery spool first runs through a first thread-advancing means, i.e., a pair of rollers, then passes subsequently through a heating device, a cooling zone, a friction twist imparter according to FIG. 1 of the drawings and then through a second pair of rollers serving as thread-advancing means and is then led towards a winding device. The yarn is hereby temporarily high-twisted to 3,000 turns per meter and heated in this condition in the heating device to 235 C. for 0.4 second. Both discs 1 and 2 of the twist imparter have a diameter of 60 mm. and, consequently, a circumference of approximately 190 The yarn has a circumference of approximately 0.29 mm, so that a transmission ratio of 1:600 is obtained. The discs 1 and leach rotate at a rotation speed'ofapproximately 1,000 turns per minute, so that the rotation speed of the A yarn will be approximately 600,000 turns per minute without considering slight slippage which will naturally occur in this process and the linear speed of the yarn through the twisting device is approximately 200 meters per minute.

From the foregoing description it will :be seen that I contribute by my invention a simple method and apparams for yarn twisting which permits of a high number of turns or twists per meter of yarn while reducing slippage to insignificant proportions.

I believe that the method and apparatus of my new invention will now be understood, and that its advantages will be fully appreciated by those persons skilled in the art.

I claim:

1. A false twist device of the class described for texturing textile yarn comprising: twist imparting members positioned to have at least partially overlapping contacting' portions at a yarn twisting zone through which yarn is advanced, means driving said members in respective directions whereby the contacting portions thereof move in opposite directions, and magnetic means urging at least one of said contacting portions towards the other frictionally to engage yarn passing through said zone and impart a false twist thereto.

2. A false twist device according to claim 1, wherein said twist imparting members are discs formed of an elastorner having a high coefficient of friction relatively to textile yarns.

3. A false twist device according to claim 1, wherein said twist imparting members are belts formed of an elastomer having a high coefficient of friction relatively to textile yarns.

4. A false twist device according to claim 1, wherein said contacting members comprise: ferromagnetic material polarized to urge the contacting portions thereof towards one another.

5. A false twist device according to claim 1, wherein a magnet is positioned relatively to said contacting members to urge the contacting portions thereof together.

6. A false twist device of the class described for texturing textile yarn comprising: twist imparting members formed of an elastomeric material and positioned to have at least partially overlapping contacting portions at a yarn twisting zone through which yarn is advanced, means driving said members in respective directions whereby the contacting portions thereof move in opposite directions, and magnetic means urging at least one of said contacting portions towards the other frictionally to engage yarn passing through said zone and impart a false twist thereto.

7. In a false twist device of the class described for texturing textile yarn comprising: twist imparting discs formed of an elastomeric material and positioned to have at least partially overlapping contacting portions at a yarn twisting zone through which yarn is advanced, at least one of said discs including magnetic material, means driving said discs in respective directions whereby the contacting portions thereof move in opposite directions, and magnetic means urging at least one of said contacting portions towards the other frictionally to engage yarn passing through said zone and impart a false twist theretO.

8. In a false twist device of the class described for texturing textile yarn comprising: twist imparting belts formed of elastomeric material and positioned to have at least partially overlapping contacting portions at a yarn twisting zone through which yarn is advanced, at least one of said belts including magnetic material, means driving said belts in respective directions whereby the contacting portions thereof move in opposite directions, and magnetic means urging at least one of said contacting portions towards the other frictionally to engage yarn passing through said zone and impart a false twist thereto.

9. In a false twist device of the class described for texturing yarn comprising: twist imparting discs formed of an elastomeric materi l and positioned to have at least partially contacting edge portions at a yarn twisting zone through which yarn is advanced, means driving said discs in respective directions whereby the contacting portions thereof move in opposite directions, and magnetic means urging at least one of said contacting portions towards the other frictionally to engage yarn passing through said zone and impart a false twist thereto, said discs being disposed angularly relatively to one another to define an an le of the order of 10 to 45 between the longitudinal axis of the yarn and the plane of the surface of each disc.

19. Apparatus according to claim 9 wherein the angle between the longitudinal axis of the yarn and the plane of the disc surface is approximately 30.

References Cited UNITED STATES PATENTS Jerrems 5777.40 XR Peck 5777.4 XR Abbott 5777.4 XR Snider 5777.4 Brown 5777.4 Van Dijk et a1. 5777.4 Henshaw 5777.4 XR

FRANK I. COHEN, Primary Examiner.

DONALD E. WATKINS, Examiner. 

1. A FALSE TWIST DEVICE OF THE CLASS DESCRIBED FOR TEXTURING TEXTILE YARN COMPRISING: TWIST IMPARTING MEMBERS POSITIONED TO HAVE AT LEAST PARTIALLY OVERLAPPING CONTACTING PORTIONS AT A YARN TWISTING ZONE THROUGH WHICH YARN IS ADVANCED, MEANS DRIVING SAID MEMBERS IN RESPECTIVE DIRECTIONS WHEREBY THE CONTACTING PORTIONS THEREOF MOVE IN OPPOSITE DIRECTIONS, AND MAGNETIC MEANS URGING AT LEAST ONE OF SAID CONTACTING PORTIONS TOWARDS THE OTHER FRICTIONALLY TO ENGAGE YARN PASSING THROUGH SAID ZONE AND IMPART A FALSE TWIST THERETO.. 